package com.ynny.exaple;

public class Circle {
    private double r;//半径
    public Circle(){
        this.r = 1;
    }
    public double getR(){
        return r;
    }
    public void setR(double r){
        this.r = r;

    }
    public double findArea(){
        double s = 3.14 * r * r;
        return s;
    }



}
